Bull Trout Status and Abundance on Warm Springs Reservation
description
Transcript of Bull Trout Status and Abundance on Warm Springs Reservation
BULL TROUT STATUS AND ABUNDANCE ON WARM SPRINGS RESERVATION
2007-157-00Cyndi Baker & Jen Graham
PROJECT HISTORY Began in 1998 to document bull trout
life history in WSR and SC and monitor population abundance
Data from 1998 to 2009 summarized in a 2011 report
Study objectives were reviewed, adjusted and/or added in 2011 categorical review project proposal
STUDY AREA
RESULTS FROM DATA COLLECTED 1998-2009
Distribution across Warm Springs Reservation
Relative abundance of juvenile bull trout/brook trout in index reaches in WSR and SC
Spawning distribution and redd counts in index reaches in WSR and SC
Migration timing and patterns Document fluvial and resident forms
Hybridization with brook trout
1998 BULL TROUT DISTRIBUTION
RELATIVE ABUNDANCE IN INDEX REACHES1999 to 2011
REDD COUNTS IN INDEX REACHES 1998-2011
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 20110
50
100
150
200
250 Warm Springs River Shitike Creek
Redd
Cou
nts
DOCUMENTING LIFE HISTORY TYPES Resident vs. fluvial that migrate to
Deschutes R. Emmigration/immigration timing
Outmigrant traps at mouth of WSR and SC Weirs for returning adults at mouth of WSR
and SC Radio Telemetry
1999-2000 2007
RADIO TELEMETRY STUDIES 1999-2000
23 implanted with radio tags and released (same vicinity where caught):
DR (n=9) WSR @ hatchery (n=9) SC at weir (n=5)
2007 23 caught below Round Butte Dam, implanted
with radio tags and released in lower Deschutes R.; 2 caught in CR:
One downstream of John Day Dam One at Lone Pine, downstream of Deschutes
R. mouth
HYBRIDIZATION WITH BROOK TROUT Tissue samples collected 1999 and
2005 WSR (n = 15 in 1999; 39 in 2005) SC (n = 30 in 1999; 40 in 2005)
Univ. Montana (Dr. Spruell) used paired interspesed nuclear element (PINE-PCR) method to amplify markers that differentiate bull – brook trout and allow identification of hybrids
Results - one F1 hybrid identified in SC
WHAT’S PROPOSED Update bull trout distribution map (last done 1998) Continue monitoring trends in index reaches in WSR and
SC and water temperatures relative abundance of bull/brook trout (add WW) redd counts (plus Whitewater R. and Jefferson Ck)
Permutation analysis determine the probability of detecting a population decline using
snorkel counts in index reaches in WSR and SC Migration patterns to describe life-history patterns
Continue operating weirs Add HDX antennae arrays
Develop bull trout length and age relationships specific to WSR and SC
Develop plan for re-establishment of bull trout in Mill Creek
EXPECTED OUTCOMES OF PROPOSED WORK Trends in relative abundance of juveniles and redd counts
provide indication of population status over time Continue monitoring juvenile abundance and redds in WSR & SC for
long-term trends Continue monitoring redds in Jefferson Ck. and Whitewater R. in
Metolius Basin Begin monitoring juvenile abundance in Whitewater R.
Bull trout distribution Update distribution map (habitat surveyors reported additional
sites) Develop plan to re-establish bull trout distribution in Mill Creek
Permutation test will validate whether indices in juvenile abundance have the power to detect 25%, 50% and 75% decline in population over 5, 15, and 30-yr period (using methods of Budy et al. 2006)
EXPECTED OUTCOMES OF PROPOSED WORK Further documentation of bull trout movement patterns
within WSR & SC to define home range of resident forms and migration timing of fluvial forms into spawning grounds Continue operating outmigrant traps and weirs Install HDX antennae in WSR & SC, PIT tag 50 bull trout/year –
year-round monitoring Bull trout released from SWW into lower Deschutes R. HDX tagged
Bull trout length and age relationships specific to WSR and SC and by life-history type Collect scale samples from fish while PIT tagging and catch at
weirs (age structure of population) Validate length at age of first spawning (could expand or contract
assumed spawning population)
HOW THESE RESULTS INFORM MANAGEMENT Bull trout are listed under the ESA – Monitoring is important to gage
recovery (Draft Bull Trout Recovery Plan) and identify management actions CTWSRO is a sovereign nation with sole management authority on the Reservation - Monitoring data
used to take management actions as identified and recovery planning Habitat restoration in Mill Creek and re-establishment of bull trout LWD placement in WSR Fish passage barriers (e.g. WSNFH)
Management of fish passage through SWW and LBC fishery LBC management of prey base (kokanee)
Release of kokanee downstream of Pelton for sockeye re-establishement Manage bull trout fishery in LBC (are Whitewater bull trout part of this fishery?) Fish passage through SWW and transported downstream of Pelton
Releasing bull trout downstream of Pelton may reduce genetically unique populations (e.g., Whitewater) Fish passage upstream
If bull trout are not passed upstream then there could be potential for competition and introgression in SC and WSR
Advancing understanding of life histories of bull trout in Deschutes Basin will aid interpretation of data
Age at length by life history types First age at spawning/frequency of spawning Genetic structure of fluvial components with respect to resident populations Contribution of fluvial/resident to spawning population Whitewater bull trout (adfluvial/resident/fluvial?), what’s the risk of entering the SWW and getting sent
downstream?